In general, a color filter is required to capture a color image by a solid-state image sensing device (image sensor). A conventionally used color filter functions as a filter which transmits only three primary colors of blue, green, and red in a visible light region, but it has low cutting ability for light in a near-infrared light region, and transmits near-infrared light. Since a silicon substrate used for the solid-state image sensing device has spectral sensitivity over a near-infrared light region in a visible light region to around 1100 nm, signals of near-infrared light are mixed with red, green, and blue signals under the influence of near-infrared light when only the conventional color filter is used, resulting in a difference with luminosity factor of human eyes.
In order to solve this problem, there has been proposed a method for eliminating the influence of near-infrared light using a near-infrared ray cut filter layer in combination with a color filter layer, and taking in only red, green and blue light into a pixel to perform photoelectric conversion. Patent Literature 1 describes a method for providing an inorganic multilayer film composed of a low refractive index material and a high refractive index material as a near-infrared ray cut filter layer under a color filter layer.
On the other hand, from the viewpoints of weight reduction and noise reduction and the like of a recent solid-state image sensing device, a thinner near-infrared ray cut filter layer has been required. Patent Literature 2 describes a method for providing a thinner near-infrared ray cut filter layer using a multifunctional polymerizable compound for a near-infrared absorptive composition for forming the near-infrared ray cut filter. From the viewpoint of improvement in image quality due to high light collection properties and high color separation properties, a thinner color pattern in a color filter for a solid-state image sensing device also has been required.
For the purpose of improving the reliability of the solid-state image sensing device, further improvement in heat resistance of a color filter and a near-infrared ray cut filter also has been demanded. Patent Literature 3 describes improvement in the heat resistance of a color filter using a specific dipyrromethene-based compound in combination with a phthalocyanine compound or a squarylium compound as a near-infrared absorbing agent.